The Time Constant in P300 Recording

Abstract

ABSTRACT A standard counting task was used to illustrate the effect of the time constant of the recording system on the amplitude and waveform of the P300 component. A random sequence of 1500 Hz (probability = .10) and 1000 Hz (probability = .90) tones was presented to one male subject. The EEG from C z and P z was recorded simultaneously at time constants of 0.1, 0.3, 1.0, and 10.0 sec. The ERP waveform was markedly affected by the time constant: the shorter the time constant, the smaller the amplitude of both the P300 and Slow Wave components.